On 5/13/2011 stem cell researchers all over the world learned that Induced pluripotent stem cell lines derived from human skin cells (iPSC) had a serious setback. “The path to the clinic has just gotten a lot murkier,” said Dr. Robert Lanza, chief scientific officer of Advanced Cell Technology (OTC:ACTC).

Investor Stem Cell is dedicated to bringing investors and stakeholders together in thoughtful discussion to educate and publicize the incredible advancements in the regenerative medicine sector.

Online PR News – 16-May-2011 – – On Friday afternoon Investor Stem Cell's website saw 5X the normal traffic volume when Yang Xu, a biologist at the University of California, San Diego published a paper in the journal Nature. Dr Xu's research was paid for by the National Institutes of Health and by California’s stem cell program (CIRM). The two part study using embryonic stem cells (hESC) and induced pluripotent stem cells (iPSC) from an inbred strain of mice and implanted those stem cells into other mice of the same strain. The animal subjects did not have an immune response to the implanted embryonic stem cells. But their immune systems attacked the implanted (iPSC) cells.

Induced pluripotent stem cells (iPSC) were first generated by Shinya Yamanaka’s team at Kyoto University, Japan in 2006 using animal skin cells and then in 2007 using human skin cells. This discovery was met with great excitement because they were not controversial. Their design did not require the destruction of human embryos and because the cells were created from the patient’s own cells would face no rejection issues.

According to extensive research by Dr. Xu since the stem cells could be made from a particular patient’s skin cells, they could be used to make tissues that presumably would not be rejected by that patient’s immune system.

Xu group’s next steps will be to scrutinize which specific cells in the teratomas trigger immune refusal, and under what circumstances. The team used two diverse techniques to make the iPS cells, and they showed slightly different predispositions to trigger immune rejection, so it may be that reprogramming methods can be fine-tuned to avoid the rejection in the future.

“We propose that the technology to generate iPS cells needs to be improved in order to minimize the difference between iPS and embryonic stem cells, so that iPS cells can be more useful in human therapies,” says Xu.

Members of Investor Stem Cell had various mixed reactions. One of the members, Superfeeed said " It is unfortunate that since the excitement of (iPSC) first swept the world, stakeholders have increasingly been made aware thst (iPSC) are not at all equal to (hESC).